Clamping device intended for the electrical connection of a work-coil for the inductive heating of work-pieces to the secondary winding of the output coil of a high-frequency



June 19, 1956 BLOK' ETAL 2,751,481

CLAMPING DEVICE INTENDED FOR THE ELECTRICAL CONNECTION OF A WORK-COILFOR THE INDUCTIVE HEATING 0F WORK-PIECES TO THE SECONDARY WINDING OF THEOUTPUT COIL OF A HIGH-FREQUENCY Filed March 15, 1952 lllllllllll" m ul"IIIIIIIIIIIIIIIIIII I l m lfiuflu INVENTORS Lourens Blok DirkChrls'rioqn Von lperen Agent United rates Patent CLAlvflING DEVECEINTENDED FOR THE ELEC- TRICAL CQNNECTFUN (PF A WQRK CGIL FOR THEINDUCTBE HEATING OF WORK-PIECE? TO THE SECGNDARY WINDING QF THE GU33 PUTCUIL ()F A HIGH-FREQUENCY Laurens Blair and Dirk fihristiaan van Iperen,iiindhorerl, Netherlands, nssignors to Hartford National Bank and TrustCompany, Hartford, Conn, as trustee Application March 15, 1952, SerialNo. 276,835 Claims priority, application Netherlands April 20, 1951 3Claims. (Cl. 219-1019) According to the invention, a clamping deviceadapted to electrically connect a work-coil for the inductive heating ofworkpieces to the secondary winding of the output coil of ahigh-frequency generator is characterised in that the clamping devicecomprises cooling channels for artificial cooling by means of a coolingagent. It is thus possible to utilize a work-coil which does notcomprise a cooling channel, since the heat produced in such a work-coilmay be sufiiciently dissipated on account of the large contact surfacewith the clamping device. It is thus also possible to utilize a verysimple work-coil which is punched, for example, from sheet material.

According to a further feature of the invention, the clamping device isadapted to clamp a work-coil which comprises two or more stackedmembers. This affords the advantage that, whilst the dimensions of theworkcoil may be adapted in a very simple manner to the length of thework-piece to be treated, it is also possible to ensure satisfactorycooling of all the work-coil members by means of a single clampingdevice.

The invention will now be explained more fully by reference to theaccompanying drawing, given by way of example, in which Figs. 1 and 2show a clamping device and a work-coil comprising two stacked plate-likemembers respectively.

In Fig. 1, two poles 1 and 2 are connected by means of bolts passedthrough apertures 3 and 4 to the two extremities of the secondarywinding of the output coil of a high-frequency generator. The terminals1 and 2 comprise two bodies 1, 5 and 2, 6 respectively, of which thebodies or members 5 and 6 are adjustable with respect to 1 and 2 bymeans of bolts 7 and 8. All the bodies are internally provided withcooling channels or cavities which empty into tubes 9. The latter areinterconnected with the use of rubber tubing, so that the cooling agentsuccessively traverses all the bodies in accordance with the dotted lineshown.

Fig. 2 shows a work-coil comprising two stacked platelike members 10 and11 of same shape, each comprising a working aperture 12 for embracing aworkpiece and slots 13 to accommodate the bolts 7 and 8 of the clampingdevice. The contact surfaces are such that the heat produced in thecoils may be sufliciently dissipated on the clamping device.

It is evident that more than two stacked members may be used. Thethickness of each working member in one practical example was 5 mms.

What we claim is:

1. A clamping device for electrically connecting a work-coil for theinductive heating of work pieces to a secondary winding of an outputcoil of a high frequency generator comprising at least one pair of heatconducting members connected to said high frequency generator, saidmembers having opposed clamping surfaces for holding at least onework-coil therebetween, means for adjustably spacing said membersrelative to one another, a workcoil clamped between said opposedsurfaces, and a plurality of cooling channels in each of said membersfor artificially cooling said members and said work-coil by means of acirculating cooling agent in said channels.

2. A clamping device for electrically connecting a work-coil for theinductive heating of work pieces to a secondary winding of an outputcoil of a high frequency generator comprising at least two pairs of heatconducting members connected to said high frequency generator, each pairof members having opposed clamping surfaces for holding electricalconnections of at least one workcoil therebetween, means for adjustablyspacing the mem bers of each pair relative to one another, a work-coilhaving electrical contacting regions clamped between said opposedsurfaces, a plurality of interconnected cooling channels in each of saidmembers for artificially cooling said members and said work-coil bymeans of a circulatory cooling agent in said channels.

3. A high frequency generator comprising an output coil with a secondarywinding, 21 solid, metallic Work-coil for the inductive heating ofwork-pieces, clamping means for electrically connecting said work-coilto said secondary winding, said clamping means including a pair ofspaced members, said Work-coil being adapted to be clamped between saidmembers and comprising a plurality of flat, superposed elements providedwith a working aperture, the contact areas for said electricalconnection being so proportioned that the heat produced in saidwork-coil is sutficiently dissipated due to contact with said clampingmeans, and a plurality of cooling channels in each of said members forartificially cooling said members and said work-coils by means of acirculating cooling agent in said channels.

References Cited in the file of this patent UNITED STATES PATENTS1,449,369 Anderson Mar. 27, 1923 2,128,086 Gakle Aug. 23, 1938 2,181,644Seifert Nov. 28, 1939 2,493,950 Dow et a1 Jan. 10, 1950 2,665,367 SeulenJan. 5, 1954 FOREIGN PATENTS 284,521 Switzerland July .31, 1952 613,322Great Britain Nov. 25, 1948 613,323 Great Britain Nov. 25, 1948

